[Coco] Ken-Ton Update

[Gene Heskett]

On Friday 19 December 2003 16:37, Chris Spry wrote:
>Well folks, I've been able to use a hard drive on this setup
> finally. I just forwent the format program and tried DSKINI'ng a
> drive and it actually did it.  All 255 RS-DOS partitions. Am trying
> to get the latest OS-9 from the project on my system to get the
> rest of the HD going on that system.  But I thought I would also
> ask a question.  I got it to detect several hard drives, but on
> most of them I get rather IO or WP errors when trying to dskini any
> of the drive.  I only got one other to work right (and it is a 1GB
> SCSI drive no less).  Anybody have any kind of answer to this?
>
>-Chris

You might want to check the terminations, Chris.  The scsi bus is a 
transmission line, and as such *must* be terminated in its 
characteristic impedance of about 120 ohms on each end of the cable.
This means the controller, unless its actually in the middle of the 
cable but is more normally at one end of the cable, must have its own 
terms turned on and powered up.

So if you have a multiplug cable, and most are, you must verify that 
the drive has its terms on and that its expecting to have the host 
card furnish the power for the terminations, which if not "active" is 
fairly substantial from the 5 volt bus.  And the drive *must* be on 
the last plug of the cable, 6" of open cable hanging out past the 
drive and its terms, will generate an echo level sufficient to mess 
with the data integrity very quickly.

That also assumes that the host card is set to provide this 
termination power.

Two or more drives can share the scsi bus because those drives closer 
to the controller would have their terms removed or turned off, at 
which point the drive, unless its responding to a query addressed to 
it, will be tri-stated and invisible to the bus.

One of those errors looked as if it might be related to the use of 
parity.  If possible, turn that on, on both the drive and the 
controller if both support it, its a great error catcher.  In any 
event, both devices have to have matching settings.

-- 
Cheers, Gene
AMD K6-III at 500mhz 320M
Athlon1600XP at 1400mhz  512M
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by Gene Heskett are:
Copyright 2003 by Maurice Eugene Heskett, all rights reserved.